Centering gauge



L.FRHMARK CENTERING GAUGE Feb. 19, 1952 5 Sheets-Sheet 1 Filed Sept. 2, 1947 HVVENTUR. opold Freimark L 1 Le BY Attorneys L. FREIMARK CENTERING'GAUGE Feb. 19, 1952 5 Sheets-Sheet 2 Filed Sept. 2, 1947 INVENTOR.

Leopold F reimark L. FREIMARK CENTERING GAUGE Feb. 19, 1952 3 Sheets-Sheet 3 Filed Sept. 2, 1947 IN V EN TOR. Y Leopold Frejmark W4 W Attorneys Patented Feb. 19, 1952 CENTERING GAUGE; e nqldilhe ma ew oxk,.li.,

Applicationseptember Qlaims-..

Thednvention relates to a machine tool orde viceforsetting, locating and centering a workpieceon a machine table in certain dimensional relationship-to the axis of its-rotating workingspindle.

My tool or -;device functions, in" addition; as a gauge for checking the accuracy of machining operations in relation-to either the-centersofholes orin relation to center lines or faces of a workpiece fr0m-which the dimensions tobe followed in machining the workpiece are given.

The 'location of holes in workpieces to be machined on jig-borers, jig-grinders,- milling machines or other machine tools is usually deter-- mined'by dimensions given from --two-adja cent sides of the workpiece.

Thesetwo sides also called -faces-,-or more accurately.their-intersection must be-aligned. withthe 'centerline of the rotatingmachine-spindle to meet accurate and" precise machiningspecifications; only after thisalignment hasbeen done,- can-the-machine table be movedtothe -desired. positionin-order-to start therequiredmachining operation While devices knownand. used for alignment of-corners andfaces of workpieces permit the eating of-one face ofthe workpieceat a'time, the setting and locating tool made inaccordance with. my i nvention-is designed for themost accurate alignment of corners formed by the intersection otanytwo sides of a workpiece or for thealignmentotfiat or curved-surfaces or faces of a work-. piece. Nip-setting tool is therefore an excellent device for locatingand for checking the align-- ment-of jigs, holding-fixtures, and vises in relation-to the axis of the machine-spindle of a machine tool.

By addinga simpleattachment, my novel tool can further be used for the positioning of centers for angular holes.

- The-invention provides further a a :meansfor checking machined surfaces of workpieces in-re-.

' lation-tofinishedholes or of machined holes in relation. to 7 previously finished surfaces of work pieces without, taking the workpiece off themachine table.

Specific objectsot the invention will appear from the description hereinafter and the features ot novelty will be pointed out in the claims In the ---accompanying I drawing, illustrating various embodiments and'means of utilizing my inventionr-Figal is a perspective view of the center-ingtool; Fig.- 2 is a perspective view of a sideplate'or'bottom-platewhich is an attachment to the centering too1-;-Fig. 3 is a perspective viewof 2, 1947;;Serial No -7 #1 710 Y 33t zilz a 2 another .attachment'toi 1 the .zcenteringdeylce gfOl locating and :zchecking centerszpfg angulap hol P e 4 s -perspectiveiviewaotthelcent net 56 Q usedizin locating. settingand .centerin one side .corner of. a workpiece;,-.-Fig'.;15;is ,a;-pelispect view ofsthe centering tool .usedjmthejnsidec n r of a workpiec .Fiss a :DQISHGG VQ we of the centeringtool USBdjOlZ-jl'lQfiligljlHltBIli} cylindrical-workpiece; Fig: 7 is; a:si de ';view tool. in use for the. al;ignment,.jofwise jaw Fig. 8;is an end view of thecentering;deilickan 1 its 1 attachment. as shown in: -Fig.;,3 :fQmansu-mr settings for the purpose of boring angulalir fisez The main element of my novel centerin device.

is a cylindrical or any. symmetrical;.geomet-ri 1 body 2 whose axis 3 .is ;located-ieith.er :exactl the intersection of. two. sides.4 and ion-atagive and known distance from theintersectiongofrthe; two sides 4 and 6, or of the two sides 5 and. or of the two sides B and fl of;a.flatgauge-block;., l which. is formed either integrally :with the 2 or is in any suitable manner connected. with; the body'2.: The thickness and the width; of the. gauge-block are preferably of standard wdimena.

sions.

The flat gauge-block I has a-pluralityofvholes 8 and-9 which may be. -threaded andwhichsg-are. scattered at regular intervals in i the sides, espee, cially the smaller sides ofgauge-block I,: so. that, a side or bottom 1ate..|u, with corresponding; holes I l;may-=be attachedtothe mainbodyzl by; screws or dowels as shownin-Fig.4,:2Figs6;and. Fig. 8 or in any-other -way suitable toiperform" the locating or checking operationeas required:

The attachment: to the-centering gauge is. .used for locating and 'checkingangular .holes .in :work-.-.. pieces (shown in-Fig.- 3 and Fig.8).-

Theattachment shown-m Fig. 3'consistswof 1a; cylindricalring I 3 and a cylindrical-spin 14 at-i: tached to ring- I3 perfectly-squareto-it and in -line; with the center ofringhole-JZ In the utilization of. the attachment, c-aszishownr in Fig. 3,the ring-.13 fits over. :theccylinderdaiof; the main gauge andis kept-in the desiredlpositionz bya-setscrewil5;

In -the gauge block :4 as wvell asein the side; plate; l0; openings 16 and l1.,";respectively,: are provided, into which powerfulmagnets are posis tioned for the-purpose of holding the centering gauge in asure and quick .manner t0...the W,0r.kpiece, provided; of--course, that the-.- workpiece. itself is magnetic; and reactse to magnetism;

In Figs. 4 to 8, inclusivethere-are-illustrated.- various ways-in :which- 'theedevice of my invention 65 may -be--used.

In Fig. 4, for instance, the alignment of a hole I8 to be drilled or bored in the work piece IS in relation to corner 20 is demonstrated. The location of the hole |8 from corner 20 is given by the dimensions A and B. The centering gauge, with plate attached to side 4 of the gauge block 1, is held to this corner 20. The machinespindle 2|, with an indicator 22 inserted in it, is rotated around cylinder 2 of the gauge and the machine table 23, with the work I9 being moved lengthwise or crosswise in known manner, until the indicator 22 shows the same reading all around the circumference of the cylinder 2. The corner is thus perfectly in line with the axis of rotation of the machine spindle. Now the table 23, which carries the work I9, is moved the distance B lengthwise and the distance A crosswise thereby setting the centerline of the machine-spindle in exact line with center of the hole l8 to be drilled or bored.

In addition, the centering tool may be used for checking the accuracy of dimensions A and B after the hole has been drilled or bored.

In Fig. 5, the centering gauge of my invention is used for the location of a corner 24 formed by the intersection of the two inner faces 25 and 2B of a workpiece 27. The gauge block I is attached to the inside corner 24 as shown. Now cylinder 2 of the centering tool has only to be utilized as previously described, in order to align the machine-spindle a-Xis 2| with the corner 24.

The centering device with its plate [0 screwed as a base to the bottom of gauge block I, as shown in Fig. 6, is used for the location of centers for holes or centerlines for slots or keyways in re- .2.

lation to the centerline, or in relation to the line of tangents, of a cylinder 28 or in relation to a point or a line of a workpiece with any geometrically curved surface. In the utilization of my device for this purpose, the side 5 of the gauge block I is placed parallel to the centerline of the cylindrical work 28 against the work. Cylinder 2 of the gauge is again utilized in the foregoing described manner and thereby the axis of rotation of the machine-spindle is perfectly aligned by the contactline of the gauge with the workpiece 28. In order to align the axis of the cylindrical workpiece 28 with the machine-spindlecenter 2|, the table carrying piece 28 (the table is not shown in Fig. 6) is moved half the diameter of the cylinder away from the spindle-axis in the direction of the centering gauge. Any other hole position on said cylindrical work may be found in like manner.

Fig. '7 illustrates the use of my centering tool for the alignment of vise-jaws in relation to the axis of rotation of a machine-spindle 2|. The gauge is placed in any suitable manner in the vise 29, preferably with side 5 of the gauge block contacting the fixed jaW 38 of the vise. Cylinder 2 of the gauge is now centered with the centerline of the machine-spindle 2| in the manner heretofore described. Thus, the face of fixed jaw is likewise positioned in theaxis of the workingspindle 2|. After removing the centering gauge from the vise, the workpiece is placed in vise 29 and'machining operations with dimensions given from the face joining the fixed jaw of the vise can be performed with highest accuracy.

Fig. 8 shows the centering tool adapted for 10- cating'angular holes. The plate In is screwed to the side of gauge block as shown and'the special attachment of Fig. 3 is mounted on cylinder 2 of the centering gauge. If now, for instance, a hole 33 is to be bored in the workpiece 32 under an angle alpha to the side 34 and the center of hole 33 is given by the distance C from corner 3|, the workpiece 32 is laid on the machine table 23 under the angle alpha and in the usual manner clamped to the table. The centerline of pin ll of the attachment Fig. 3 is set in the given angle alpha to the side 5 of the gauge block l in known manner either by a sinebar, by a protractor, or by other known means, and then kept in position by the setscrew I5 (Fig. 3).

The gauge, thus made ready for this particular use, is held to corner 3| either by its own weight or by the magnetic inserts l6 and I! (Fig. 1 and Fig. 2). Pin l4 and therefore corner 3| is located in the axis of the machine-spindle 2| in the manner described heretofore, the table 23 moved lengthwise the distance 0 and thereby the centerline for the angular hole 33 is brought in line with the machine-spindle-center.

As will be seen from the above description, the centering device of my invention is a simple but accurate device for locating a side or the intersection of two sides in relation to the axis of rotation of any working spindle. The centering tool may be used also for the positioning of holes in cylinders or in bodies whose outside is formed by any kind of geometric curved surfaces. Furthermore, the invention may be adapted to locate angular holes in workpieces by addinga simple attachment to the centering device.

In addition, my centering tool may be used for checking finished machining operations in relation to some previously finished face or intersection of faces or for checking machined sides in relation to previously machined holes or slots.

I claim:

1. A centering and checking tool comprising a gauge block and a cylindrical geometric body secured to the gauge block, with the axis of said body in line with the line of intersection of two adjacent lines of said gauge block, a plate in juxtaposition with said gauge block, and in which the gauge block is provided with a plurality of threaded apertures by means of which said plate,

having corresponding apertures therein, may be secured to said gauge block in different positions whereby said plate aids in properly positioning said gauge block.

2. A centering device in the form of a gauge block the body of which comprises an exact right parallelepiped having true planar faces joined to a right cylinder, the axis of said cylinder being a linear continuation of one edge of said parallelepiped.

3. A centering device comprising two rectangular gauge blocks of like height connected together so as to form an internal right angle and another cylindrical gauge block secured to one of said firstnamed gauge blocks and so disposed that its axis is a linear continuation of the intersection of the surfaces of said firstnamed gauge blocks enclosing said angle.

4. The centering device of claim 3, including.

an attachment for use in securing oblique angular settings, said attachment comprising a ring having a radial cylinder extending outward therefrom, said ring being adapted to be fitted over said cylindrical gauge block.

5. A centering device comprising a first gauge block the body of which is a right parallelepiped joined to a right cylinder, the axis of said cylin--- der being a linear continuation of one edge of saidparallelepiped, and a second gauge block thebody; of which is a right parallelepiped, both gauge blocks being provided with matching apertures whereby the second block may be secured to the parallelepipedonal portion of the first to form an internal right angle the apex of which is in line with said axis.

LEOPOLD FREIMARK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1 1,330,069 Fischacher Feb. 10, 1920 1,408,098 Knapp Feb. 18, 1922 Number 6 Name Date, Boucher Oct. 14, 1930 Hetherington Apr. 16, 19 5 Miller June 25, 1935 Mosher Apr. 16, 1940 Reich May 21, 1940 Whitmore Sept. 4, 1945 Berry Mar. 11, 1947 Calow Mar. 11, 1947 Rizor Feb. 10, 1948 OTHER REFERENCES American Machinist, Dec. 9, 1943, page 103. 

